1. Field of the Invention
The present invention generally relates to a three-dimensional model modification system for modifying a three-dimensional model defined by plural surfaces, a method of the same, a computer-readable program of the same, and a computer-readable recording medium storing the program, and more particularly to a three-dimensional model modification system that can modify a three-dimensional model in a short time while keeping the design intention unchanged, a method of the same, a computer-readable program of the same, and a computer-readable recording medium storing the program.
2. Description of the Related Art
Conventionally, there has been known a three-dimensional model modification system for modifying (morphing) a three-dimensional model (three-dimensional figure) defined by plural surfaces, a method of the same, and a computer-readable program of the same.
In the meantime, however, when a three-dimensional model is being globally modified using, for example, an enlarge/reduce function in a commercially available CAD system, it is not possible to modify the three-dimensional model while keeping the design intention unchanged. For example, when an operator wishes to keep a circular form unchanged during the modification, there is a high possibility that the circular norm will be changed into an ellipsoidal form as the modification is performed.
In view of the above point, there have been proposed systems intended to globally modify a three-dimensional model while keeping the design intention unchanged by setting plural constraint points in the three-dimensional model (See for example, Patent Documents 1 and 2).
Patent Document 1 discloses a system modifying a three-dimensional model modification system by setting one or more operating points on a cross-sectional contour of the three-dimensional model and moving the operating points to set a target contour figure; thus the three-dimensional model is modified by moving the one or more operating points to generate the target contour figure.
Patent Document 2 discloses a system in which one or more operating points are set on a surface of a three-dimensional model, the operating points are moved on the surface of a target three-dimensional model, and thus the model is globally modified based on the movement of the operating points.
Patent Document 1: Japanese Patent Application Publication No: 2002-269586
Patent Document 2: Japanese Patent Application Publication No: 2004-78309
However, in a conventional system, it is not possible to keep the design intention under plural restraint conditions. For example, when a three-dimensional figure including plural surfaces mutually constrained by each other is being globally modified under prescribed constraint conditions using a parametric function of commercially available CAD software, it requires an enormous number of arithmetic steps and enormous processing time.
Furthermore, in systems disclosed in Patent Documents 1 and 2, since it is necessary to set the operating points on plural of surfaces of a three-dimensional model and move each operating point to modify the entire three-dimensional model, it requires time and effort to set the operating points and it is difficult to set the operating points in advance while having an image of the modified figure (design). In addition, when moving the operating points, it is difficult to obtain the modified image figure of the three-dimensional model, therefore the design intention of the operator may not be reflected in the modified model.
The present invention was made to solve the problems, it is a primary object of the present invention to provide a three-dimensional model modification system that modifies a three-dimensional model in a shorter time while keeping the design intention of the three-dimensional model substantially unchanged, a method of the same, a computer-readable program of the same, and a computer-readable recording medium storing the program.